From March 1, 1995, the Union ministry of surface transport will register only those cars in the metropolitan cities that are equipped with catalytic convertors -- all in order to enforce the use of unleaded petrol.

The move follows requests by the Union ministry of environment and forests to help out in the slow phasing out of highly polluting leaded petrol. However, the so-called unleaded petrol will also contain lead, but in negligible quantities -- less than 0.013 gm per litre. Sources in the petroleum ministry said that limited addition of lead in vehicular fuel was necessary to avoid "knocking".

The MEF and the Union petroleum ministry have decided to introduce unleaded petrol in a phased manner only because of problems like inadequate capacity to supply unleaded fuel, and manufacturing catalytic convertors. The ministry has agreed, in principle, to supply enough fuel for the cars that hit the roads after March 1.